The present invention relates to electrical connector assemblies and, more specifically, to a moisture sealing grommet for use in such assemblies that provides for sealing of the contacts contained in such assemblies against moisture over a range of wire diameters for the wires connected to the contacts and passing through the grommet.
Electrical connector assemblies generally include a plug and a receptacle, each of which contains a dielectric insert that has electrical contacts retained within bores in the inserts. The rear portion of the assembly contains a sealing grommet, through which the wires connected to the contacts pass, and which grommet seals the contacts contained in the insert from moisture. An example of the type of connector assembly to which the present sealing grommet may be applied is the type of connector illustrated in U.S. Pat. No. 4,082,398, assigned to the assignee of the present invention, the contents of which are incorporated by reference herein. A further example of a type of connector assembly, containing a sealing grommet, to which the present sealing grommet may be applied is the type of connector assembly illustrated in U.S. Pat. No. 3,221,292, also assigned to the assignee of the present inventor, the contents of said patent also being incorporated by reference herein. The grommet described in U.S. Pat No. 3,221,292 contains two webs in each of the axial passages, a terminal web and inner web, with the inner web of one passage being misaligned with the inner web of an adjacent passage.
The moisture sealing capability of the grommet has taken an additional significance due to the requirement for reduced weight, for example on aircraft, and the increasing use of low current carrying circuits, which have resulted in a decrease in the diameter of wires leading to the contacts within an insert and which pass through and must be supported by the grommet, as well as sealed by the grommet to protect the contacts from moisture. Insulation thickness on wires has also been reduced, which increases the chances of an inefficient seal within conventional grommets. The importance of such a moisture seal is evidenced by the specifications required, for example, in connectors designed to Military Specification, MIL-C-38999G, and the humidity or moisture sealing requirements designated therein.
With the use of smaller diameter wires, such wires must be carefully supported outside the grommet to prevent elongation of sealing webs, used in conventional moisture sealing grommets, and thereby reduce or destroy the moisture sealing properties of the webs of the grommet that seal the contacts contained in the insert from moisture.